I keep my ~25 year old Ti-83 or 84 from middle and high school in my shop because I find using it while working on stuff with dirty hands much easier than my phone or tablet. I just need something which basically never needs new batteries and lets me use parentheses to group expressions and the occasional trig function. I think the current batteries are almost ten years old now.

I use a junky $5 calculator when I'm working with my mill and lathe. It's easier to have the little thing there at hand in the machine shop to do quick calculations than to have a whole computer.

I have an old HP 15C RPN scientific calculator.

- I know where the buttons are without looking.

- It has functions my Android calculator does not have (directly or that I know of).

- It has a strange satisfying tactile feedback.

- It never interrupts me. Ever.

- It never distracts me. Ever.

I reach for it frequently.

- I have a HP 16C, mainly for doing number conversions (DEC-HEX-BIN) and binary arithmetic.

- I have a HP 15C to take with me all the time (due to its small form factor).

- I have a HP 48 GX as main calculator, it is most feature complete and has a clock and alarms. I use it a lot for time calculations.

- I have a HP 48 SX, but did not use it much any more after acquiring the 48 GX.

- I have a HP 10bII+, which was a gift of my brother in law when he saw my obsession with HP calculators. I do not use it much, as I am not in financial stuff.

- I have a HP 41 CV, which is less capable as my 48 GX, but I somehow love it so much, that it resides on my desktop and is used a lot.

- I have a Casio Classpad fx-CP400, which I use when I tutor my nephew - it is the best fit for high school requirements (in Germany).

- I have a bunch of TI nspire and voyagers and a TI 83 plus, that I never use.

- I have a TI-92 plus which I used a lot in the past, but I do not like it anymore.

- I have a Casio FX-730P, which I like to write little programs for.

Not to mentions my collection of slide rules.

There's a farm here in Zurich where we buy a lot of our groceries. The store is unmanned. You use their calculator (or your cellphone calculator) to add up what you're buying then use your phone to scan a QR code and pay.

Oi! You forgot adding machines. Big buttons, +/- features, auto-tax. And! Inexplicably none of the pre-installed calculators emulate them—bizarre.

And yes, I do use an adding machine, Sharp EL-1750

My HP32s from ~40 years ago still resides on my workbench where I mess around with RF circuits for fun. It has no graphing capability and it's barely programmable, but that's ok, I keep an actual computer nearby for those sorts of things. The calculator keeps earning new batteries bc tinkering with analog circuits I frequently want to evaluate little things like AB/(A+B) or 1/2piF or (1+S)/(1-S), or need the log 10 or square root or the cosine of something.

In those circumstances, the calculator's compact form factor is quite convenient, compared to needing two hands at the computer keyboard, or one handedly hunt-pecking said keyboard. As for the mouse, that has to be the slowest, most focus stealing option of them all. The calculator doesn't take much room, so it can be kept within arm's reach without getting in the way, quickly gives me the numbers I need, without demanding I become fully engaged with it.

Also, those old HP buttons are just so nice to press, a refreshing break from the dead flat glass you get everywhere else these days.

Yes, I have a Casio fx-9750GIII and I love it. I still haven't found an Android app or website that can do everything that I need (basic functionality), but in general:

- I need physical buttons. I often find that on touchscreens I mistype something and I don't notice.

- The history feature. Maybe I want to do a serial task or calculation, and I can just replace/correct one of the formulas in the history and it automatically recalculates all of the expressions that came after it.

- I have written some micropython code / utilities for the calculator and I use it all the time.

- I don't want to context switch to do a quick calculation. On my PC I have to open up a new terminal or a website (I might be offline, so I have to hotspot and then connect the wifi and ...) and interrupt my existing work or I have to frequently switch between a PDF or latex or whatever that I'm working on.

- Typing out `sin` or `np.sin` or `sin^-1` on PC is both longer and more error prone. It gets very frustrating very quickly.

- The numerical solver is a godsend. Try solving for the roots of an expression like `xe^x = 10` on your PC without internet. Or with an android application. On my calculator it's just a few dedicated button presses. On the PC, I have to use isympy and typeout `nsolve(Eq(x * exp(x), 10), 1)`, and you wouldn't even get a proper graphical display of the expression while you are typing it.

I'm using a HP48G. [0]

It's just a joy to use and i also like it a lot design wise.

I like that it has a big display for 4 RPN rows, but i admit that that's something software calculators would even be better at.

It definitely has a nostalgic/romantic side to it for me.

Oh and for every day stuff, i really like to use Spotlight on macOS. It's really convenient: Command+Space, then just type the expression into the search box.

[0] https://en.wikipedia.org/wiki/HP_48_series

I think you accidentally a verb.

But, yes. Casio fx-991EX. It's designed for schools, I think, but at the time it was the most advanced one they made that wasn't a graphing calculator, since I figured that if I ever wanted to draw a graph I'd just fire up "Grapher", which is still bundled with every Mac.

In about a decade I think I've done that once. The Casio is great.

Looks like it's discontinued now? I guess the fx-9910CW is the replacement. They made the buttons circular. Weird.

I have Sharp EL506T and it serves me well. I don't use it very often, mind, but it still happens semi-regularly.

The biggest reason for me are physical buttons and the fact I know the layout and capabilities. I'm just faster on physical calculator than on Android app.

But to tell the truth, usually I just use Speedcrunch on my computer. Or spreadsheeds. Or Python REPL.

I still have my Casio FX-83MS which my mother purchased for me when I started secondary school 24 years ago. It still works, it usually sits on my desk, and I use it a couple of times per month.

During my bachelors, I was using a Casio FX-991ES+. It was a beautiful calculator compared to the hand-me-down Fx-82 VPAM. And pretty popular with the folks of my age that time.

During and after grad school, I was using Mathematica or NumPy/Sympy quite a bit. But it felt like using an overpowered system to do basic assignments. Think of taking a Bugatti Veyron for grocery shopping. I indulged myself with another physical calculator - this time a Casio FX-CG50 with a color display and python support. I use it whenever I do self-paced courses or reading the occasional stats/ML paper.

I don't, but I sometimes see them used here in Japan. Some small-shop operators use them to add up charges and show the total to the customer. I was recently in the office of a small company, and I noticed that the bookkeeper had a calculator next to a pile of paper (receipts?) on her desk. She also had a computer in front of her with a spreadsheet on the screen.

When I moved here forty-three years ago, it was common to see abacuses used in similar situations. There's still an abacus school [1] not far from where I live, but it's been a long time since I saw one in use.

[1] https://maps.app.goo.gl/nvTg4hfSjTcba47c8

TI-30Xa still sits on the corner of my desk along with a pen and small notepad. I use it 2-3 times a week. Still faster to reach for it than find the calculator app on my phone or PC for simple tasks.

The first time I went to China and spoke basically no Mandarin (just "want", "don't want", "this one", "that one", "how much money", "thank you") I took a cheap calculator when I went shopping for electronics and just let people type in the price they wanted. It was also useful for haggling too.

Yes. When accounting I use a cheap calculator to do quick sums. Easier than using a calculator on the computer desktop.

Button feedback, reduced chance of fat fingered mistype. Doesn’t tie up phone holding numbers on screen.

Yes, not for its technological features but for its single-purpose-ness. If I'm working on paper, it's nice to pull out rather than a full on computer which also has all of my email on it.

Yeah I still use my good ol' TI-83+ occasionally, but I'm a math instructor, so obviously. Most often I'll just use GNU `bc` though.

We are getting away from them in the classroom though; just started piloting a program where students use the Desmos app on their phones (requested to be in airplane mode) in class, and we have a department set of air-gapped phones with Desmos pinned for students to use on exams.

Oh dude, no. The instant I could start using something like https://www.wolframalpha.com/ in college over a decade ago, I did. I've never, not once in my life, had any desire to use a physical calculator when I could use a full blown computer instead. I think it's inferior even for pedagogy purposes - I can't screenshot and make Anki cards out of a TI-84.

I use a Casio. Not just calculator, but for any tool, I try to avoid using my phone. A phone is a rabbit hole. Once you pick it up, you never know what notification will interrupt your flow. Besides, for these utility apps are difficult to monetize, it's hard to find one that isn't bombarded with ads. Even if luckily you find a perfect one, the creator might lose interest and stop maintaining it next year, forcing you to change your usage habits.

Yes, I do. At my workbench, I find them much faster and more convenient than using my phone or a computer.

I use a Casio HL-815L to manage my checkbook. I lost the ability to do this math in my head about 10 years ago. I am 77.

Nope, spotlight search handles basic calculations, python repl the rest of them.

I still regularly use a TI-35, and / or an old slide rule (I have three), and / or rough mental order of magnitude guesstimates.

Otherwise I use domain software for other tasks.

I still use a high school calculator for doing pen and paper maths. Stuff like figuring out when functions change sign. I find it less distracting than a code editor

I keep my TI-84 at my desk and reach for it maybe once a week. Usually for money reasons though, not so much for work stuff.

I do. It just works, and it feels better than the on-screen versions. The Windows calculator is atrocious. Some of the emulators for iOS are good, but still feel clumsy in comparison to the real thing, especially for more than adding two short numbers.

The truth is: I like calculators, and I think almost everyone answering in the positive does too. Most people don't care about them, and see their phone as a god-given miracle, I guess, which makes calculators an expensive-ish burden.

I use a SwissMicros DM16L (a HP16C clone) because I like RPN and prefer physical buttons over a touchscreen.

Haven't used one since the day I finished school. I still have it though. It's like an artifact from another time...

Does Windows Calc.exe count as well? :-))

My kids often use their hands, I sometimes use paper and pencil

Mines are stored, but I use the hp48 emulator regularly.

For over a decade I've been using emulators of the calculators I grew up using on all my android phones. I see no point in changing my "weird" ways.

I use RealCalc for most things (RPN style). Has many functions like a scientific, but I mostly stick to the basic four and it also converts units.

I switch to Graph89 when I need a graph/table involving trig or polynomial approximations. Sometimes I'll even write a basic program. If I'm using this app I probably also have measuring tools out for a DIY project.

I go to spreadsheets for anything beyond that using "Office: Planmaker". It handles the xlsx format perfectly! That's how I do my monthly budget, health tracking, etc. For reasons beyond my understanding, some people are still impressed seeing proper full-featured spreadsheets done quickly on a phone.

HP-16C

Casio fx81

I use only the HP once in a while for old times sake.

I still have them, also a slide rule, but no, I don't use them. It is essential to have these for when the grid breaks like it currently has in Mississippi for over a week. I also have multi-decade-storage batteries for them.

I actually own one, a Casio. Simple reason, I'm a ham radio operator and you need one for the exams.

tl;dr: RPN - ride or die. ;)

Sometimes, for vintage reminiscing, a real HP48GX.* It got me through AP Calculus BC, SAT-I, and EE/CS. And doubled as a learning TV remote & TV-B-Gone. I also have a virtual HP48 on my phone, tablets, and computers.

In middle school, I had an HP 32SII. I remember being able to hear** either the processor clock or data line(s) of each of the 32 and 48 because one or more components acted as inadvertent audio oscillators that would make noises during computation (and during idle on the 48 because it had to keep redrawing the clock).

I've used R, MATLAB, pspice, and Mathematica in the past.

I'm a fan of Xcas and Wolfram Alpha now.

* I also have a collection of HP 48[GS]X cards, the printer, and the overhead projector adapter. In lieu of the overpriced official HP 48G to computer RS-232 interface cable, one can be easily made from a Sony CD-ROM audio cable.

** With my much younger ear pressed up to it.

"Do you still physical calculators?"

Well, no. My calculators don't bounce around so I have no reason to "still" them. /s

I have a calculator app that I use 99.9% of the time. I have a physical calculator around here somewhere. I used to use it when I'd have to tabulate physical items or when I'd been doing calculations for a long time. Short bursts on my phone are fine, but over hours is kinda troublesome.